1. Field of the Invention
The present invention relates to the field of medicament dispensing systems. More particularly, the invention relates to a chain-driven robotic arm for use in a system that automatically stores and dispenses pre-packaged pharmaceutical products and other products, wherein the robotic arm is compatible with closely spaced, densely packed product shelves.
2. Description of the Related Art
Pharmacists spend an increasing amount of time educating patients about proper use and handling of medicaments and pharmaceuticals. While this trend toward more patient counseling increases patients' knowledge about medicaments and decreases improper use of medicaments, it leaves less time for pharmacists to fill and dispense medicaments.
Automatic medicament dispensing systems have been developed to assist pharmacists in filling and dispensing prescriptions and to therefore have more time for patient counseling. Some of these systems are effective for filling and dispensing medicaments in the form of pills and capsules, but they are not designed to dispense larger pre-packaged pharmaceuticals. Pharmacists in many areas dispense large quantities of pre-packaged boxes and/or bottles of pharmaceuticals and currently must manually locate and dispense these items, reducing the amount of time those pharmacists have for patient counseling.
Another problem with manually locating and dispensing pre-packaged pharmaceuticals is that errors are sometimes made. For example, many boxes of pre-packaged pharmaceuticals look alike even though they have different strengths or quantities of medicaments therein. Pharmacists therefore occasionally locate and dispense the wrong box. Such errors can obviously have serious consequences for patients receiving such products.
Additionally, as some packages of pharmaceuticals may be of different sizes and/or shapes, mechanical devices often have difficulty gripping individual packages. Furthermore, in gripping a package, a mechanical device may disturb other packages, making future retrieval of those disturbed packages more difficult.
Automated systems have been developed which more effectively store products on shelves. One such medicament storage system is disclosed in U.S. Pat. No. 6,883,681, entitled “AUTOMATIC DISPENSING SYSTEM FOR UNIT MEDICAMENT PACKAGES”, filed Dec. 8, 1999, and incorporated into the present application by reference. This system includes a product transporter with a conveyor belt on the transporter. The transporter acquires a product when positioned so that an end of the transporter conveyor belt is proximate, for example, an end of an infeed conveyor belt. The product is transferred from the infeed conveyor belt to the transporter conveyor belt when both belts are rolling in the same direction so that the product engages the transporter conveyor belt as it reaches the end of the infeed conveyor belt. While this system is effective for use with certain products, it is not ideal for use with products contained in narrow packages that may wobble and/or overturn as they encounter a narrow gap when passing from one conveyor belt to another, disrupting the storing or dispensing process.
Furthermore, many automated systems are not adapted to store products on shelves so that the products are in close proximity to each other. Gripping arm mechanisms such as the manipulator arm and gripping fingers of known devices are not well adapted for reaching onto a shelf, particularly a deep shelf, to place or remove a product. While similar arms with greater length may be used to reach farther onto a shelf, such a design reduces the number of products that can be stored on the shelf.
An arm with greater reach requires more lateral shelf space to operate, which requires the products to be stored farther apart. As the length of the arm increases, so does the radius of curvature of the path followed by the end of the arm. Similarly, if the arm is made to pivot up and away from a shelf, the shelves must be placed further apart to accommodate the swing path of the arm. Accommodating the increased operating space of such systems results in less densely packed products, product shelves spaced farther apart, and/or shelves with less depth.
Various approaches have been implemented in an attempt to overcome some of these problems. For example, co-pending U.S. patent applications entitled “ROBOTIC ARM FOR USE WITH PHARMACEUTICAL UNIT OF USE TRANSPORT AND STORAGE SYSTEM”; Ser. No. 10/996,256, filed Nov. 23, 2004, and “FORK BASED TRANSPORT STORAGE SYSTEM FOR PHARMACEUTICAL UNIT OF USE DISPENSER”, Ser. No. 10/896,477, filed Jul. 22, 2004, both of which are incorporated herein by reference, each disclose various medicament retrieval apparatuses. However, these approaches often rely on pivoting arms that require increased mechanical complexity and precise orientation.